Container body



W. B. ELAM CONTAINER BODY Sept], 1964 Filed Dec. 28, 1961 R M m M m M V m m 4 4 41m. l m M a W @E MM llTTOE/VEY5 United States Patent The present invention relates to spirally wound fibre containers and has particular reference to a body construction for such containers wherein an impervious tape is folded around the raw edge of a paper-backed aluminum foil liner ply to prevent wicking of the container contents into the main fibre body plies.

A recent development in the packaging industry has been the utilization of spirally wound, fibre bodies containers for an increasing number of products, many of which either constitute or include as components, penetrating fluids such as oil, grease, water, or moisture.

To protect the main fibre body plies from these fluids, the fibre bodies of these containers are usually lined with a helical liner ply which comprises a very thin aluminum foil inner layer which is prelaminated to a paper backing layer which supports and strengths the foil layer and prevents it from tearing during the formation of the body. The helical marginal edge portions of this liner ply are usually disposed in overlapping relationship to form a helical lap seam. If suitable protection is not provided, the fluid has an opportunity to wick into the exposed overlap edge of the paper backing layer of the liner ply and eventually reach and weaken the main body plies which lie behind the liner ply. With some products, the wicking action is so pronounced that it precludes use of this type of body construction.

To prevent this wicking action, the present invention contemplates the utilization of a narrow tape of a material, such as aluminum foil, which is impervious to the fluid and is folded around the exposed overlap marginal edge portion of the liner ply and secured in place by an adhesive which is also impervious to the fluid product. As a result, the edge of the paper backing layer of the liner ply is shielded from the fluid and penetration of the latter into the main fibre body plies is effectively eliminated.

An object of the invention therefore is the provision of a fluid-tight spirally Wound fibre container body wherein the exposed edge of the interior lap seam of the helical liner ply is shielded from the fluid product in the container to prevent wicking of the product into the body plies.

Another object of the invention is the provision of such a body wherein such protection is obtained at minimum cost by a very narrow ribbon of sealing tape.

Still another object is the provision of a simple method of forming such a container body.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

FIGURE 1 is a perspective View of a sealed container having a spirally wound body which embodies the principles of the instant invention;

FIG. 2 is an enlarged sectional detail taken substantially along the line 22 in FIG. 1; and

FIG. 3 is a schematic drawing illustrating the instant method of forming the leakproof spirally wound container body of FIGURES 1 and 2.

As a preferred and exemplary embodiment of the instant invention, FIG. 1 discloses a sealed container 10 comprising a spirally wound body 12 and a pair of imperforate end closure members 14 which are secured to the opposite ends of the body 12 in end seams 16 of any suitable configuration to provide tight joints which prevent leakage of the fluid product (not shown) which is packed in the container It). The body 12 is built up of a plurality of helically wound plies which are preferably adhesively secured together to form a solid, strong, body structure. In the illustrated body, these plies comprise an exterior label ply 18, an outer main fibre body ply 20, an inner main fibre body ply 22 and an interior liner ply 24. It will be understood, however, that the number and thicknesses of the various body plies may be varied to meet the specific. requirements of any given product or package.

The label ply 18 preferably comprises a protective outer aluminum foil layer 26 which is prelaminated to a backing layer 28 which is formed of a reinforcing material such as kraft paper or the like. The label ply 18 has its helical marginal edge portions overlapped to form a lap seam 3i and provides an impervious external body layer which protects the body against the elements during shipment and storage.

The main body plies 20, 22 are preferably formed of a strong fibre material such as kraft paper or chipboard and have their helical edges disposed in abutting relationship to form butt joints 32, 34 which are offset from each other, as best seen in FIG. 2.

The liner ply 24 comprises an inner aluminum foil layer 36 which is prelaminated to a reinforcing backing layer 38 which comprises a strong fibre material such as kraft paper. The aluminum foil layer 36 is completely impervious to the fluid product in the container, but the fibre kraft paper layer 38 is not.

The helical marginal edge portions 39, 40 of the liner ply 24 are overlapped to form a lap seam 41 wherein the portion 39 comprises the underlap portion and the portion 40 comprises the overlap portion.

In order to prevent exposure of the raw edge of the kraft backing layer 38 in the overlap portion 40'to the fluid product, a narrow sealing tape 42 is folded around overlap portion 40 and is adhesively sealed to both its foil layer 36 and its kraft backing layer 38 by an impervious adhesive 44 which preferably covers the entire inner surface of the tape 42. The tape 42 is made of a material which is impervious to the fluid which is to be packed with in the container 10, and preferably comprises very thin aluminum foil. The adhesive 44 preferably is a thermoplastic or pressure sensitive adhesive which is adherent to both aluminum foil and kraft paper, and is impervious to the product which is to be packed in the container 10. One example of a suitable adhesive is the thermoplastic polyamide resin adhesive disclosed in US. Patent 2,840,- 264 issued to James H. Grooves. Among other types of adhesives which are suitable are those comprising copolymers of vinyl chloride and vinyl acetate, either alone or in admixture with maleic anhydride or vinyl alcohol modified vinyl chloride-vinyl acetate copolymers.

The tape 42 is also sealed to the foil layer 36 of the underlap portion 39 by an impervious adhesive 46 which is similar or identical in composition to the adhesive 44. As a result of this construction, a full foil to foil lap seam construction is obtained and penetration of the fluid through the lap seam 41 is prevented. The result is a fluid-tight container body 12 which is suitable for the packing of many types of fluid products.

FIG. 3 schematically illustrates the preferred method of producing the container body 12 of FIGURES 1 and 2. In such method, the plies 18, 20, 22, 24 are wound around the cylindrical mandrel 50 of a spiral winding machine 52 to form them into a tube 54 Which is subsequently out along lines of severance 56, which may be preprinted on the label ply 18, to produce individual bodies 12. If desired, a suitable label pattern (not shown) may also be preprinted on the label ply 18 between the lines 56 and in parallelism therewith so that each body 12 will be provided with a complete unitary label.

The mandrel 50 is anchored at one end in a block 58 which forms a part of the winding machine 52, the other end of the mandrel 50 being free to permit discharge of the finished tube 54.

In the instant method, the impervious tape 42 is adhesively secured in place on the liner ply 24 as the latter approaches the mandrel 50. To accomplish this, the tape 42 is pulled from a supply roll 58 and fed against an adhesive applying roller 62 which applies the adhesive 44 to one of its surfaces. The marginal trailing edge portion of the liner ply 24, which subsequently is to become the overlap portion 40 of the lap seam 41, is then brought into right angled relationship with the adhesively coated surface of the tape 42 along the center line of the latter and the tape 42 and the liner ply 24 and fed into a plow or folder unit 64 which is provided with a pair of oppositely twisting cam surfaces which gradually bend the tape 42 around the opposite sides of the liner ply 24 and press it into face to face engagement therewith to adhesively secure it in place thereon.

Thereafter, the liner ply 24, with the tape 42 secured to it, is passed beneath an adhesive applying roll 66 which coats the outer surface of the tape 42 with the impervious adhesive 46. The liner ply 24 is then helically wound around the mandrel 50 in such manner that its marginal edge portions are overlapped to form the lap seam 41.

The inner body ply 22, the inner surface of which has been coated with a suitable adhesive 68, is then butt wound around the wound liner ply 24, and the outer body ply 20, the inner surface of which is coated with a suitable adhesive (not shown), is butt wound around the inner liner ply 22.

The partially formed tube 54 is then passed through a continuously driven endless belt 70 which forms a part of the winding machine 52 and operates around a driving drum 72 and an idler drum 74. The endless belt 70 is wrapped around the mandrel 50 and is maintained in tight engagement with the outer surface of the tube 54 so that it moves it helically along the mandrel 50 and pulls the various plies 18, 20, 22 and 24 from their supply rolls (not shown).

After the tube 54 emerges from the belt 70, the label ply 18 is wrapped around it to complete the tube 54, which then is discharged over the free end of the mandrel 50 and is severed into individual bodies 12.

Only the adhesives 44, 46 have been illustrated in FIG. 2, the other adhesives being omitted for the sake of clarity of illustration.

4 It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction, and arrangement of the parts and that changes may be made in the steps of the method described and their order of accomplishment without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim: 1. A multi-ply container body for holding a fluid product without leakage, said body comprising a helical fibrous body ply, a helical liner ply disposed inwardly of said body p y, said liner ply comprising an inner layer which is impervious to said fluid product and a paper backing layer which is pervious to said fluid product, said liner ply completely covering the inner surface of said body ply and having its opposite marginal edge portions overlapped to form an interior helical lap seam having an underlap portion and an overlap portion, and a strip of impervious tape folded around the edge and extending along both surfaces of said overlap portion, said impervious tape being secured to the impervious layer of said overlap portion and to the impervious layer of said underlap portion by an adhesive which is impervious to said fluid product to prevent the penetration of said fluid product through said lap seam and into said body ply. 2. The body of claim 1, wherein the inner layer of said liner ply comprises aluminum foil, and wherein said im pervious tape comprises aluminum foil.

References Cited in the file of this patent UNITED STATES PATENTS 1,390,644 Ritchie Sept. 13, 1921 2,795,366 Magil June 11, 1957 2,891,714 Vallas June 23, 1959 2,901,162 Vallas Aug. 25, 1959 2,988,970 Geist June 20, 1961 3,042,286 Pottle July 3, 1962 FOREIGN PATENTS 683,206 Great Britain Nov. 26, 1952 

1. A MULTI-PLY CONTAINER BODY FOR HOLDING A FLUID PRODUCT WITHOUT LEAKAGE, SAID BODY COMPRISING A HELICAL FIBROUS BODY PLY, A HELICAL LINER PLY DISPOSED INWARDLY OF SAID BODY PLY, SAID LINER PLY COMPRISING AN INNER LAYER WHICH IS IMPERVIOUS TO SAID FLUID PRODUCT AND A PAPER BACKING LAYER WHICH IS PREVIOUS TO SAID FLUID PRODUCT, SAID LINER PLY COMPLETELY COVERING THE INNER SURFACE OF SAID BODY PLY AND HAVING ITS OPPOSITE MARGINAL EDGE PORTIONS OVERLAPPED TO FORM AN INTERIOR HELICAL LAP SEAM HAVING AN UNDERLAP PORTION AND AN OVERLAP PORTION, AND A STRIP OF IMPERVIOUS TAPE FOLDED AROUND THE EDGE AND EXTENDING ALONG BOTH SURFACES OF SAID OVERLAP PORTION, SAID IMPERVIOUS TAPE BEING SECURED TO THE IMPERVIOUS LAYER OF SAID OVERLAP PORTION AND TO THE IMPERVIOUS LAYER OF SAID UNDERLAP PORTION BY AN ADHESIVE WHICH IS IMPERVIOUS TO SAID FLUID PRODUCT TO PREVENT THE PENETRATION OF SAID FLUID PRODUCT THROUGH SAID LAP SEAM AND INTO SAID BODY PLY. 